Boston Dynamic's BigDog is already an impressive and freakishly animal-like beast, but Darpa it seems has bigger plans in mind and is asking for a smarter, bigger BigDog. The upgraded robot needs to carry 400 pounds of payload, run 20 miles on any terrain and survive un-refueled for a whole day to please Darpa's request. Plus it must be way quieter so it's more useful in real combat situations and have a smarter brain so it can steer itself autonomously as it trots after its soldier masters.It'll have to cope with stairs, water hazards, desert levels of heat and arctic levels of snow and ice, navigate through GPS waypoints, and it'll have to respond to speech and gesture commands—at which point you imagine a soldier commanding it to "sit!" and giggle slightly. But only slightly, as none of these enhancements seem too beyond the pale, given the already amazing development of BigDog. Just one sad point though: Darpa's labelling the new machine the "Legged Squad Support System" or L3. Would it have been a bit much for the military eggheads at the defense research agency to exercise their imaginations and dub it K9? Much better name. [FedBizOpps via DangerRoom]